Synthesis and Structure of Pregelatinized Starch-Modified SiO2 Gels for Strength Enhancement of Portland Cement

Here, we introduce novel pregelatinized starch-modified silica gels for Portland cement enhancement. The modified SiO2 gels demonstrate superior mechanical properties compared to pure silica, with optimal starch modification increasing the modulus by 244.8%. Structural characterization reveals that starch alters Si-O bond configurations without covalent bond formation. Applied to Portland cement, the modified gels significantly enhance compressive strength through method-dependent mechanisms. Casting applications show measurable strength improvements, while pressing methods achieve a 42.3% compressive strength increase with superior packing efficiency under confined conditions. The enhancement primarily stems from accelerated C3S hydration facilitated by the modified silica gels. These findings establish an innovative approach for high-performance cement materials via organic–inorganic composite modification, providing practical formulation guidance across diverse application scenarios.